The present invention relates generally to a structure of an alternating current meter for measuring the power consumption, and more particularly to an electronic digital measuring structure of the alternating current meter, which is capable of converting the power consumption rate of a power user into a digital signal output. A precision measurement of the power consumption is thus made possible by the digital signal output.
The induction- type alternating current meter is a principal instrument which is used by the power company to measure the power consumption by a power user. The collection of the power consumption data by the power company is done by a person who is hired by the power company to read the meter on site. Such a general practice as described above is not cost-effective and is inefficient at best in view of the fact that the wages and the fringe benefits of the meter-person give an added adminstrative cost, and that the manual reading of the power meter by the meterperson is apt to be erroneous.
The traditional alternating current meter has inherent deficiencies in light of its measurement of the power consumption being done mechanically. There is often a great disparity between a mechanically-measured value and an actual consumption value. As shown in FIGS. 1 and 2, a prior art alternating current meter 10 comprises a voltage magnet 11 (as shown in FIG. 2) capable of generating a movable magnetic field, and a metal disk 12 which is located over the voltage magnet 11 such that the metal disk 12 is induced by the movable magnetic field to turn. As a result, a center shaft 13 of the metal disk 12 actuated to turn by the metal disk 12 in motion. One of tow gears 151 of a counter 15 is meshed with a worm rod 14 which is mounted on the center shaft 13 such that the worm rod 14 turns along with the center shaft 13. As the revolving speed of the metal disk 12 is transmitted to the counter 15, the numerical reading is shown by the counter 15 as a result of the cumulative measuring and switching, which are attained by a plurality of gear trains of the counter 15. In light of the inherent manufacturing tolerance and the error of the engagement ratio of the transmission members of the prior art meter 10, the numerical reading shown by the counter 15 of the meter 10 is not a reliable reflection of the actual power consumption.
It is therefore the primary objective of the present invention to provide a digital meter for measuring the alternating current. The digital meter comprises a light-emitting element and a light sensor for conversion of a power consumption rate into a digital signal, which is then processed by a processing unit such that the power consumption is expressed in various forms, such as watts, cash value, etc.
It is another objective of the present invention to provide a digital meter for measuring the power consumption. The digital meter is electronically linked with a local area network via which the power company gathers the power consumption data of a power user without the use of a meter-person.